!A!Pictorial!Essay!of!Common!and!Uncommon!CT!Findings!of ... Pictorial... ·...
1
A Pictorial Essay of Common and Uncommon CT Findings of Le9 Upper Quadrant Abdominal Pain Jenny Lu MD and Bernard Chow MD INTRODUCTION Abdominal pain is the most common chief complaint of paDents presenDng to the emergency department. The differenDal diagnosis of le9 upper quadrant pain can be divided into organs located in the le9 upper quadrant including the lung, stomach, spleen, le9 kidney, pancreas, bowel, and mesentery. In this exhibit, we will review the imaging features of some of the common and uncommon causes of le9 upper quadrant pain on CT and briefly highlight the general clinical management of the more uncommon eDologies so that the radiologist can aid the referring clinician in forming a management plan in the acute clinical seNng. LUNGS Fig 1. 40yearold woman presents to the ER with le: flank pain. A. Axial image in lung windows shows a small focal consolidaBon in the basilar segment of the le: lower lobe. B. Coronal sequence of the abdomen and pelvis on this CT ureteral stone protocol study shows a small nonobstrucBve stone in the inferior pole of the le: kidney. Le. lower lobe pneumonia This case illustrates the importance of evaluaDng the lung bases on ureteral or abdominal CT. Pneumonia may be followed with chest radiography at least 4 weeks a9er appropriate medical treatment. S. pneumoniae pneumonia will clear radiographically in 60% of healthy paDents less than 50 years old by 4 weeks and in 25% of older paDents with bacteremic pneumonia, COPD, alcoholism, or underlying chronic illness. ESOPHAGUS/STOMACH Fig 2. 55yearold male presents to the ER with upper abdominal pain a:er swallowing a fish bone. A. Linear density in the gastric antrum which is likely penetraBng the anterior, if not the posterior wall with small focus of adjacent extraluminal gas. B. The falciform ligament is outlined by intraperitoneal free air. A B A B Foreign body in the gastrointesGnal tract Most foreign bodies pass through the gastrointesDnal tract unevenVully within 1 week and GI perforaDon is rare, occurring in less than 1% of paDents. Fish bones are the most commonly ingested objects and appear as a linear calcified lesion someDmes associated with thickened intesDnal segment, localized pneumoperitoneum, regional fa\y infiltraDon, or associated intesDnal obstrucDon. SensiDvity of CT for detecDon of intra abdominal fish bones is 71.4% with the limiDng factor being observer awareness. A C B Fig 3. 89yearold female with persistent le: upper abdominal pain status post recent admission for parBal small bowel obstrucBon. A. Axial image contrast enhanced CT shows a parBally rimenhancing extraluminal fluid collecBon adjacent to the distal esophagus and free fluid in the le: upper quadrant. B. CommunicaBng rimenhancing fluid collecBon causing mass effect on the adjacent le: hepaBc lobe and stomach, a new finding compared to prior CT 2 weeks ago. C. SagiTal sequence image shows the rim enhancing fluid collecBon causing mass effect on the adjacent stomach predominantly involving the gastric fundus with wall thickening and inflammaBon. Boerhaave Syndrome with le. upper abdominal fluid collecGon Boerhaave Syndrome typically occurs in le9 side of distal thoracic esophagus with fullthickness tear following vomiDng or straining. If there is suspicion for Boerhaave syndrome, may consider CT with oral contrast or esophogram with watersoluble contrast. If no leak is idenDfied with water soluble contrast, examinaDon should be repeated with thin barium to evaluate for subtle leaks. CT findings include extraluminal gas and fluid collecDons in the lower mediasDnum and/or upper abdomen. Large perforaDons require surgical intervenDon and drainage of fluid while small selfcontained perforaDons are managed nonoperaDvely with broad spectrum anDbioDcs. SPLEEN A B Fig 4. 58yearold female presents to the ER with le: upper abdominal pain. A. Axial image of a contrastenhanced CT with oral contrast shows a round so: Bssue mass just inferior to the spleen with adjacent fat stranding. B. SagiTal image shows an arterial branch arising from the splenic artery terminaBng along the superior aspect of this round so: Bssue mass. Splenule infarct Splenules occur in 1030% of autopsies and represent failure of fusion of splenic rests forming in the dorsal mesogastrium during development. Splenules are known to occur on vascular pedicles and are thus at risk for torsion. Infarcted splenules are rare and may present as a rounded so9 Dssue density of lower a\enuaDon than the spleen with surrounding stranding and a vessel visualized coursing towards the splenic artery, visualized 43.3% of the Dme. Treatment is conservaDve and nonsurgical as involuDon and atrophy are the natural history of infarcted splenic Dssue. KIDNEY Fig 5. 42yearold female presents with fever and le: flank pain. Axial image on delayed excretory phase contrast enhanced CT shows striated nephrogram in the le: kidney. Acute pyelonephriGs RouDne radiologic imaging is not required for diagnosis or treatment of uncomplicated cases of acute pyelonephriDs, but imaging may be required in paDents who fail appropriate medical therapy within the first 72 hours (approximately 5% of paDents) and paDents at risk for severe complicaDons (i.e., diabeDc, elderly, or immunocompromised paDents). Of note, 75% of all renal abscesses occur in diabeDc paDents. Typical imaging findings on contrast enhanced CT include one or more areas of wedgeshaped poor enhancement that extends from papilla to cortex. Imaging abnormaliDes persist over 1 to 5 months and delay in healing results in persistent pyuria. A B Fig 6. 90yearold female presented to the ER with le: abdominal pain. A. Axial noncontrast enhanced CT shows le: hydronephrosis and perinephric stranding secondary to a UPJ obstrucBon. B. SagiTal sequence image of the le: kidney shows suggesBon of a crossing vessel at the level of the UPJ obstrucBon. Ureteropelvic obstrucGon UPJ obstrucDon most commonly is a congenital parDal proximal ureteral obstrucDon detected in utero or later in life. The exact cause remains unknown, but may be due to an intrinsic cause such as abnormality of the collagen or muscle. Secondary causes such as strictures from iatrogenic causes, inflammaDon, or tumor are less common. The presence of crossing vessels are important to note for surgical planning, but are not usually the cause of UPJ obstrucDon. Typically presents with pyelocaliectasis with abrupt narrowing at the UPJ. Symptoms include intermi\ent abdominal pain and flank pain a9er drinking large volumes of fluid or fluids with diureDc effect. Treatment with retrograde endopyelotomy or surgical pyeloplasty may be indicated in symptomaDc paDents or in paDents with asymmetric or impaired renal funcDon. PANCREAS A B C Fig 7. 56yearold male presents with upper abdominal pain. A. Axial image contrast enhanced CT shows an enlarged gallbladder with cholelithiasis as well as stranding and free fluid in the le: upper quadrant. B. Decreased enhancement of the body and tail of the pancreas with adjacent fat stranding concerning for acute pancreaBBs with necrosis. There is also associated splenic vein thrombosis. C. Coronal sequence image shows splenic vein thrombosis extending into the proximal main portal vein. Acute PancreaGGs Most common causes are alcoholism and cholelithiasis. CT features in mild pancreaDDs include normalappearing pancreas to diffuse enlargement, heterogeneous a\enuaDon, and peripancreaDc fat stranding. Severe pancreaDDs has addiDonal CT findings of lack of normal enhancement of the pancreas consistent with necrosis and associated complicaDons including focal fluid collecDons, infected necrosis, pancreaDc abscess, pseudocysts, or venous thrombus, most commonly involving the splenic vein. Of note, pancreaDc necrosis is more apparent a9er 72 hours. Treatment is usually conservaDve: NPO, analgesics, and anDbioDcs. MESENTERY A B C Fig 8. 67yearold male presents with 3 month history of le: flank pain. A and C. Axial and Coronal sequence contrast enhanced CT images show slightly increased aTenuaBon of the jejunal mesentery with a thin surrounding rim and a number of slightly prominent mesenteric lymph nodes in this region. B. Magnified axial view shows subtle halo of fat surrounding the mesenteric vessels and lymph nodes consistent with a “fat ring sign”. Sclerosing MesenteriGs Sclerosing mesenteriDs is chronic inflammaDon of the mesentery of unknown eDology, usually involving the small bowel mesentery. It can coexist with malignancies including lymphoma, breast cancer, lung cancer, melanoma, and colon cancer. Three subgroups exist: mesenteric panniculiDs characterized by chronic inflammaDon, mesenteric lipodystrophy by fat necrosis, and retracDle mesenteriDs by fibrosis. BOWEL A B Fig 9. 35yearold female presents to the ER with le: upper abdominal pain and fever. A and B. Axial and coronal sequence contrast enhanced CT with oral contrast show segmental bowel wall thickening and extensive fat stranding surrounding a dense diverBculum in the proximal descending colon. Acute DiverGculiGs DiverDculosis is common affecDng 510% of populaDon over 45 years of age and 80% of people over the age of 85 years. Typical CT findings of acute diverDculiDs include segmental wall thickening with inflammatory changes in the adjacent fat. The key to disDnguishing diverDculiDs from other inflammatory condiDons is the presence of diverDcula in the involved colonic segment. CT can idenDfy the presence of associated complicaDons such as diverDcular abscess, perforaDon, and colovesical fistula. Of note, someDmes it may be difficult to disDnguish acute diverDculiDs from colon cancer by CT alone and Dssue diagnosis may be required. Treatment typically includes oral anDbioDcs in uncomplicated diverDculiDs with a clear liquid diet. Complicated diverDculiDs may require percutaneous abscess drainage and/or surgery. A B C Fig 10. 32yearold female with history of gastric bypass surgery presents with le: flank pain. A, B, and C. Coronal, SagiTal, and Axial sequence images on a noncontrast CT show encapsulated fat stranding within the omentum in the le: hemiabdomen. Omental infarcGon Omental infarcDon is rare due to the abundance of collateral vessels in the omentum. The right inferior porDon of the omentum is more vulnerable to omental infarcDon due to more tenuous blood supply. Primary omental infarcDon is o9en hemorrhagic resulDng from vascular compromise. Secondary omental infarcDon may occur a9er traumaDc injury as a result of surgical trauma or inflammaDon, o9en occurring near surgical site rather than right lower quadrant. CT findings include mild haziness in the fat anterior to the colon in early or mild infarcDon versus a fa\y, large (>5cm) encapsulated mass, with so9 Dssue stranding adjacent to the colon. Treatment is pain management with NSAIDs. CT findings of sclerosing mesenteriDs range from subtle increased a\enuaDon of the mesentery to a solid so9 Dssue mass, which may contain calcificaDons. The “fat ring sign” in which there is preservaDon of fat around vessels and nodes may help disDnguish sclerosing mesenteriDs from lymphoma, carcinoid, or carcinomatosis. Surgical excisional biopsy is required for diagnosis. Treatment may consist of steroids, colchicine, immunosuppressive agents, or orally administered prednisone. Surgical excision is someDmes a\empted. References (1) Craig WD, Wagner BJ, et al. From the archives of the AFIP: PyelonephriDs: RadiologicPathologic Review. Radiographics 2008; 28: 255276. (2) Federie MP. Boerhaave Syndrome. STATdx Premier. Web. 9 October 2013. (3) Goh BK, et al. CT in the preoperaDve Diagnosis of Fish Bone PerforaDon of the GastrointesDnal Tract. AJR 2006; 187:710714 (4) Horton KM, et al. CT EvaluaDon of the Colon: Inflammatory Disease. Radiographics 2000; 20:399418. (5) Horton KM, et al. CT Findings in Sclerosing MesenteriDs (PanniculiDs): Spectrum of Disease. Radiographics 2003; 23: 15611567. (6) Jonisch AI, et al. Infarcted Splenule—a case report. Am Soc Emergency Radiol 2007; 14:123125. (7) Kamaya A, et al. Imaging manifestaDons of Abdominal Fat Necrosis and Its Mimics. Radiographics 2011; 31: 20212034. (8) Lawler LP, et al. Adult Ureteropelvic JuncDon ObstrucDon: Insights with Threedimensional MulDDetector Row CT. Radiographics 2005; 25: 121134. (9) Niederman MS, et al. Guidelines for the Management of Adults with Communityacquired Pneumonia. Am J Respir Crit Care Med 2001; 163:17301754 (10) Yousef Y, et al. Laparoscopic Excision of Infarcted Accessory Spleen. Journal of Laparoendoscopic and Advanced Surgical Techniques 2010; 20: 301303.
Transcript of !A!Pictorial!Essay!of!Common!and!Uncommon!CT!Findings!of ... Pictorial... ·...
A Pictorial Essay of Common and Uncommon CT Findings of Le9 Upper Quadrant Abdominal Pain Jenny Lu MD and Bernard Chow MD INTRODUCTION Abdominal pain is the most common chief complaint of paDents presenDng to the emergency department. The differenDal diagnosis of le9 upper quadrant pain can be divided into organs located in the le9 upper quadrant including the lung, stomach, spleen, le9 kidney, pancreas, bowel, and mesentery. In this exhibit, we will review the imaging features of some of the common and uncommon causes of le9 upper quadrant pain on CT and briefly highlight the general clinical management of the more uncommon eDologies so that the radiologist can aid the referring clinician in forming a management plan in the acute clinical seNng.
LUNGS
Fig 1. 40-‐year-‐old woman presents to the ER with le: flank pain. A. Axial image in lung windows shows a small focal consolidaBon in the basilar segment of the le: lower lobe. B. Coronal sequence of the abdomen and pelvis on this CT ureteral stone protocol study shows a small nonobstrucBve stone in the inferior pole of the le: kidney.
Le. lower lobe pneumonia This case illustrates the importance of evaluaDng the lung bases on ureteral or abdominal CT. Pneumonia may be followed with chest radiography at least 4 weeks a9er appropriate medical treatment. S. pneumoniae pneumonia will clear radiographically in 60% of healthy paDents less than 50 years old by 4 weeks and in 25% of older paDents with bacteremic pneumonia, COPD, alcoholism, or underlying chronic illness. ESOPHAGUS/STOMACH
Fig 2. 55-‐year-‐old male presents to the ER with upper abdominal pain a:er swallowing a fish bone. A. Linear density in the gastric antrum which is likely penetraBng the anterior, if not the posterior wall with small focus of adjacent extraluminal gas. B. The falciform ligament is outlined by intraperitoneal free air.
A B
A B
Foreign body in the gastrointesGnal tract Most foreign bodies pass through the gastrointesDnal tract unevenVully within 1 week and GI perforaDon is rare, occurring in less than 1% of paDents. Fish bones are the most commonly ingested objects and appear as a linear calcified lesion someDmes associated with thickened intesDnal segment, localized pneumoperitoneum, regional fa\y infiltraDon, or associated intesDnal obstrucDon. SensiDvity of CT for detecDon of intra-‐abdominal fish bones is 71.4% with the limiDng factor being observer awareness.
A C
B
Fig 3. 89-‐year-‐old female with persistent le: upper abdominal pain status post recent admission for parBal small bowel obstrucBon. A. Axial image contrast enhanced CT shows a parBally rim-‐enhancing extraluminal fluid collecBon adjacent to the distal esophagus and free fluid in the le: upper quadrant. B. CommunicaBng rim-‐enhancing fluid collecBon causing mass effect on the adjacent le: hepaBc lobe and stomach, a new finding compared to prior CT 2 weeks ago. C. SagiTal sequence image shows the rim-‐enhancing fluid collecBon causing mass effect on the adjacent stomach predominantly involving the gastric fundus with wall thickening and inflammaBon.
Boerhaave Syndrome with le. upper abdominal fluid collecGon Boerhaave Syndrome typically occurs in le9 side of distal thoracic esophagus with full-‐thickness tear following vomiDng or straining. If there is suspicion for Boerhaave syndrome, may consider CT with oral contrast or esophogram with water-‐soluble contrast. If no leak is idenDfied with water-‐soluble contrast, examinaDon should be repeated with thin barium to evaluate for subtle leaks. CT findings include extraluminal gas and fluid collecDons in the lower mediasDnum and/or upper abdomen. Large perforaDons require surgical intervenDon and drainage of fluid while small self-‐contained perforaDons are managed nonoperaDvely with broad-‐spectrum anDbioDcs.
SPLEEN
A B
Fig 4. 58-‐year-‐old female presents to the ER with le: upper abdominal pain. A. Axial image of a contrast-‐enhanced CT with oral contrast shows a round so: Bssue mass just inferior to the spleen with adjacent fat stranding. B. SagiTal image shows an arterial branch arising from the splenic artery terminaBng along the superior aspect of this round so: Bssue mass.
Splenule infarct Splenules occur in 10-‐30% of autopsies and represent failure of fusion of splenic rests forming in the dorsal mesogastrium during development. Splenules are known to occur on vascular pedicles and are thus at risk for torsion. Infarcted splenules are rare and may present as a rounded so9 Dssue density of lower a\enuaDon than the spleen with surrounding stranding and a vessel visualized coursing towards the splenic artery, visualized 43.3% of the Dme. Treatment is conservaDve and nonsurgical as involuDon and atrophy are the natural history of infarcted splenic Dssue.
KIDNEY
Fig 5. 42-‐year-‐old female presents with fever and le: flank pain. Axial image on delayed excretory phase contrast enhanced CT shows striated nephrogram in the le: kidney.
Acute pyelonephriGs RouDne radiologic imaging is not required for diagnosis or treatment of uncomplicated cases of acute pyelonephriDs, but imaging may be required in paDents who fail appropriate medical therapy within the first 72 hours (approximately 5% of paDents) and paDents at risk for severe complicaDons (i.e., diabeDc, elderly, or immunocompromised paDents). Of note, 75% of all renal abscesses occur in diabeDc paDents. Typical imaging findings on contrast enhanced CT include one or more areas of wedge-‐shaped poor enhancement that extends from papilla to cortex. Imaging abnormaliDes persist over 1 to 5 months and delay in healing results in persistent pyuria.
A B
Fig 6. 90-‐year-‐old female presented to the ER with le: abdominal pain. A. Axial noncontrast enhanced CT shows le: hydronephrosis and perinephric stranding secondary to a UPJ obstrucBon. B. SagiTal sequence image of the le: kidney shows suggesBon of a crossing vessel at the level of the UPJ obstrucBon.
Ureteropelvic obstrucGon UPJ obstrucDon most commonly is a congenital parDal proximal ureteral obstrucDon detected in utero or later in life. The exact cause remains unknown, but may be due to an intrinsic cause such as abnormality of the collagen or muscle. Secondary causes such as strictures from iatrogenic causes, inflammaDon, or tumor are less common. The presence of crossing vessels are important to note for surgical planning, but are not usually the cause of UPJ obstrucDon. Typically presents with pyelocaliectasis with abrupt narrowing at the UPJ. Symptoms include intermi\ent abdominal pain and flank pain a9er drinking large volumes of fluid or fluids with diureDc effect. Treatment with retrograde endopyelotomy or surgical pyeloplasty may be indicated in symptomaDc paDents or in paDents with asymmetric or impaired renal funcDon. PANCREAS
A
B
C
Fig 7. 56-‐year-‐old male presents with upper abdominal pain. A. Axial image contrast enhanced CT shows an enlarged gallbladder with cholelithiasis as well as stranding and free fluid in the le: upper quadrant. B. Decreased enhancement of the body and tail of the pancreas with adjacent fat stranding concerning for acute pancreaBBs with necrosis. There is also associated splenic vein thrombosis. C. Coronal sequence image shows splenic vein thrombosis extending into the proximal main portal vein.
Acute PancreaGGs Most common causes are alcoholism and cholelithiasis. CT features in mild pancreaDDs include normal-‐appearing pancreas to diffuse enlargement, heterogeneous a\enuaDon, and peripancreaDc fat stranding. Severe pancreaDDs has addiDonal CT findings of lack of normal enhancement of the pancreas consistent with necrosis and associated complicaDons including focal fluid collecDons, infected necrosis, pancreaDc abscess, pseudocysts, or venous thrombus, most commonly involving the splenic vein. Of note, pancreaDc necrosis is more apparent a9er 72 hours. Treatment is usually conservaDve: NPO, analgesics, and anDbioDcs. MESENTERY
A
B
C
Fig 8. 67-‐year-‐old male presents with 3 month history of le: flank pain. A and C. Axial and Coronal sequence contrast enhanced CT images show slightly increased aTenuaBon of the jejunal mesentery with a thin surrounding rim and a number of slightly prominent mesenteric lymph nodes in this region. B. Magnified axial view shows subtle halo of fat surrounding the mesenteric vessels and lymph nodes consistent with a “fat ring sign”.
Sclerosing MesenteriGs Sclerosing mesenteriDs is chronic inflammaDon of the mesentery of unknown eDology, usually involving the small bowel mesentery. It can coexist with malignancies including lymphoma, breast cancer, lung cancer, melanoma, and colon cancer. Three subgroups exist: mesenteric panniculiDs characterized by chronic inflammaDon, mesenteric lipodystrophy by fat necrosis, and retracDle mesenteriDs by fibrosis.
BOWEL
A
B
Fig 9. 35-‐year-‐old female presents to the ER with le: upper abdominal pain and fever. A and B. Axial and coronal sequence contrast enhanced CT with oral contrast show segmental bowel wall thickening and extensive fat stranding surrounding a dense diverBculum in the proximal descending colon.
Acute DiverGculiGs DiverDculosis is common affecDng 5-‐10% of populaDon over 45 years of age and 80% of people over the age of 85 years. Typical CT findings of acute diverDculiDs include segmental wall thickening with inflammatory changes in the adjacent fat. The key to disDnguishing diverDculiDs from other inflammatory condiDons is the presence of diverDcula in the involved colonic segment. CT can idenDfy the presence of associated complicaDons such as diverDcular abscess, perforaDon, and colovesical fistula. Of note, someDmes it may be difficult to disDnguish acute diverDculiDs from colon cancer by CT alone and Dssue diagnosis may be required. Treatment typically includes oral anDbioDcs in uncomplicated diverDculiDs with a clear liquid diet. Complicated diverDculiDs may require percutaneous abscess drainage and/or surgery.
A B
C
Fig 10. 32-‐year-‐old female with history of gastric bypass surgery presents with le: flank pain. A, B, and C. Coronal, SagiTal, and Axial sequence images on a noncontrast CT show encapsulated fat stranding within the omentum in the le: hemiabdomen.
Omental infarcGon Omental infarcDon is rare due to the abundance of collateral vessels in the omentum. The right inferior porDon of the omentum is more vulnerable to omental infarcDon due to more tenuous blood supply. Primary omental infarcDon is o9en hemorrhagic resulDng from vascular compromise. Secondary omental infarcDon may occur a9er traumaDc injury as a result of surgical trauma or inflammaDon, o9en occurring near surgical site rather than right lower quadrant. CT findings include mild haziness in the fat anterior to the colon in early or mild infarcDon versus a fa\y, large (>5cm) encapsulated mass, with so9 Dssue stranding adjacent to the colon. Treatment is pain management with NSAIDs.
CT findings of sclerosing mesenteriDs range from subtle increased a\enuaDon of the mesentery to a solid so9 Dssue mass, which may contain calcificaDons. The “fat ring sign” in which there is preservaDon of fat around vessels and nodes may help disDnguish sclerosing mesenteriDs from lymphoma, carcinoid, or carcinomatosis. Surgical excisional biopsy is required for diagnosis. Treatment may consist of steroids, colchicine, immunosuppressive agents, or orally administered prednisone. Surgical excision is someDmes a\empted.
References (1) Craig WD, Wagner BJ, et al. From the archives of the AFIP: PyelonephriDs: Radiologic-‐Pathologic Review. Radiographics 2008; 28: 255-‐276. (2) Federie MP. Boerhaave Syndrome. STATdx Premier. Web. 9 October 2013. (3) Goh BK, et al. CT in the preoperaDve Diagnosis of Fish Bone PerforaDon of the GastrointesDnal Tract. AJR 2006; 187:710-‐714 (4) Horton KM, et al. CT EvaluaDon of the Colon: Inflammatory Disease. Radiographics 2000; 20:399-‐418. (5) Horton KM, et al. CT Findings in Sclerosing MesenteriDs (PanniculiDs): Spectrum of Disease. Radiographics 2003; 23: 1561-‐1567. (6) Jonisch AI, et al. Infarcted Splenule—a case report. Am Soc Emergency Radiol 2007; 14:123-‐125. (7) Kamaya A, et al. Imaging manifestaDons of Abdominal Fat Necrosis and Its Mimics. Radiographics 2011; 31: 2021-‐2034. (8) Lawler LP, et al. Adult Ureteropelvic JuncDon ObstrucDon: Insights with Three-‐dimensional MulD-‐Detector Row CT. Radiographics 2005; 25: 121-‐134. (9) Niederman MS, et al. Guidelines for the Management of Adults with Community-‐acquired Pneumonia. Am J Respir Crit Care Med 2001; 163:1730-‐1754 (10) Yousef Y, et al. Laparoscopic Excision of Infarcted Accessory Spleen. Journal of Laparoendoscopic and Advanced Surgical Techniques 2010; 20: 301-‐303.
